Abstract: This study was carried out to evaluate the growth and performance of three oyster mushroom species: Pleurotus oestreatus, Pleurotus oestreatus-florida and Pleurotus sajor-caju on khat leftover substrate. The moisture content of khat solid medium was adjusted to 55-60% and was filled in plastic bags (16×33 cm in size). The plastic bags were then autoclaved at 121°C for 90 min. After inoculation, the bags were kept in laboratory in absence of light and ventilation. The treatments were laid out in Complete Randomized Design (CRD) with eight replications. The result of the experiment indicated that Pleurotus sajor-caju gave significantly higher Number of Primodial Formation (NPF), fresh (FWFB) and Dry Weight Fruiting Body (DWFB) production than the rest of tested oyster mushrooms. The highest FWFB was obtained from Pleurotus sajor-caju (422.36 g kg‾1 of dry substrate). The lowest FWFB (221.20 g kg‾1) was observed from Pleurotus oestreatus-florida. A decline of FWFB, DWFB and NPH was observed with iincreasing time of harvesting. Biological Efficiency (BE) of Pleurotus sajor-caju was significantly higher than those obtained from other two oyster mushrooms, although the data indicated lowest BF when compared with previously reported for oyster mushroom. For this result, we can conclude that khat leftover is the relatively suitable substrate for Pleurotus sajor-caju cultivation. Further research study would be recommended on different methods of pretreatments of khat leftover and optimal formulation of suitable substrate by adding different high nitrogen containing materials to improve the productivity on khat leftover.